It must be horrible to suffer with allergies. People are always asking me if I worked with my bees lately. From what I can see, I can charge almost whatever I want for my honey and it will sell. The local ag store sells for me and he really pushes me to raid my hives, because he says that as soon as it hits his shelf, people start coming in that he never saw before telling him they heard he had honey and they need some for their allergic child. I really need to get on the ball in the spring.
I, personally, like to use elder. I make a glycerine soap with it which helps out with various skin irritations. I also might make a tea or put the leaves in pockets for heat rash. I have also put leaves in diapers for rashes. Not sure what it would for allergies, but I don't think it would hurt.